Standard electronic transformer and delay lead compensation circuit and working method thereof

Abstract

The invention discloses a standard electronic transformer and a delay lead compensation circuit and a working method thereof. The delay lead compensation circuit for the standard electronic transformer comprises a voltage divider and a phase shift circuit, the voltage divider comprises a voltage transformer T3, a resistor Ra and a resistor Rb, the first end of the primary side of the voltage transformer T3 receives an initial voltage signal, and the second end of the primary side of the voltage transformer T3 is grounded; the phase shift circuit comprises a resistor R1, a resistor R2, a capacitor C1, a resistor R3, a virtual ground and a first operational amplifier U1. The signal output end of the first operational amplifier U1 is used for outputting an advanced compensation voltage signal. The standard electronic transformer comprises a delay lead compensation circuit for the standard electronic transformer, and further comprises a mutual inductance circuit, a front-end driving circuit, a conversion circuit, a main control circuit and a sending module. The working method is based on the standard electronic transformer.

Description

Technical Field

[0001] The present invention relates to the field of power systems, and in particular to a standard electronic mutual inductor and a delay-advance compensation circuit and a working method thereof. Background Art

[0002] Smart substations are important platforms for building a strong smart grid and realizing intelligent control and regulation, and they have broad application prospects. Among the main equipment in smart substations, electronic transformers and analog input merging units are widely used. Accuracy testing of electronic transformers and analog input merging units is very important, as it is related to the safe operation of the power grid and the fairness of metering and billing. Since the testing of electronic transformers or analog input merging units uses an electronic transformer calibrator or merging unit calibrator, the accuracy testing of the electronic transformer calibrator or merging unit calibrator affects the accuracy testing of the electronic transformers and analog input merging units. Existing testing of electronic transformer calibrators or merging unit calibrators uses electronic transformer calibrator calibration devices or merging unit calibrator calibration devices.

[0003] In the existing technology, traditional electronic transformer tester calibration devices or combined unit tester calibration devices all perform accuracy tests on electronic transformer testers and combined unit testers based on the synchronization method. When applied to electronic transformer testers or combined unit testers based on the rated delay method, the accuracy of the calibration work will deviate, thereby affecting the safe operation of the power grid and the fairness of metering and billing, causing losses to enterprises or users. Summary of the Invention

[0004] The purpose of the present invention is to provide a standard electronic transformer and its delay lead compensation circuit and working method, so as to solve the problem mentioned in the above background technology that when the traditional calibration device is applied to an electronic transformer calibrator or a combined unit calibrator based on the rated delay method, the calibration accuracy will deviate, thereby affecting the safe operation of the power grid and the fairness of metering and billing, causing losses to enterprises or users.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a delay lead compensation circuit for a standard electronic transformer, comprising: a voltage divider, the voltage divider including a voltage transformer T3, a resistor Ra, and a resistor Rb, wherein a first end of the primary side of the voltage transformer T3 receives an initial voltage signal, a second end of the primary side of the voltage transformer T3 is grounded, a second end of the secondary side of the voltage transformer T3 is connected to the first end of the primary side of the voltage transformer T3, a first end of the resistor Ra is connected to the first end of the secondary side of the voltage transformer T3, a first end of the resistor Rb is connected to the second end of the resistor Ra, and a second end of the resistor Rb is connected to the second end of the secondary side of the voltage transformer T3; The phase-shift circuit includes a resistor R1, a resistor R2, a capacitor C1, a resistor R3, a virtual ground, and a first operational amplifier U1. The first end of the resistor R1 is connected to the first end of the resistor Rb, the first end of the resistor R2 is connected to the second end of the resistor R1, the first end of the capacitor C1 is connected to the first end of the resistor R1, the first end of the resistor R3 is connected to the second end of the capacitor C1, the virtual ground is connected to the second end of the resistor R3 and the second end of the resistor Rb, the non-inverting input end of the first operational amplifier U1 is connected to the first end of the resistor R2, the inverting input end of the first operational amplifier U1 is connected to the first end of the resistor R3, the signal output end of the first operational amplifier U1 is connected to the second end of the resistor R2, and the signal output end of the first operational amplifier U1 is used to output a lead compensation voltage signal.

[0006] In a second aspect of the present invention, a standard electronic transformer is provided, comprising the delay lead compensation circuit for the standard electronic transformer provided in the above embodiment, and further comprising a mutual inductance circuit, a front-end drive circuit, a conversion circuit, a main control circuit and a sending module; wherein, A mutual inductance circuit is used to collect power data of a standard signal source device, convert the power data of the standard signal source device, and obtain an initial voltage signal; The time delay lead compensation circuit is used to divide the voltage and advance the phase according to the initial voltage signal from the mutual inductance circuit to obtain an advance compensation voltage signal; A front-end driving circuit is used to convert the lead compensation voltage signal from the delay lead compensation circuit to obtain a differential voltage signal; A conversion circuit, configured to perform digital conversion based on the differential voltage signal from the front-end driving circuit to obtain an initial sampling value; A main control circuit is used to convert the initial sampled values ​​from the conversion circuit to obtain a sampled value message; The sending module is used to transmit the sampling value message of the future autonomous control circuit to the tester under test.

[0007] Optionally, the mutual inductance circuit is connected to a standard signal source device, the first primary side end and the second primary side end of the voltage transformer T3 of the delay lead compensation circuit are both connected to the mutual inductance circuit, the front-end drive circuit is connected to the second primary side end of the voltage transformer T3 of the delay lead compensation circuit and the signal output end of the first operational amplifier U1, the conversion circuit is connected to the front-end drive circuit, the main control circuit is connected to the conversion circuit, the sending module is connected to the main control circuit, and the sending module is connected to the tester under test.

[0008] Optionally, the mutual induction circuit includes a precision voltage transformer T1, a precision current transformer T2, a precision resistor Rc, a switching switch and a potential tracking module U11; the first end of the primary side and the second end of the primary side of the precision voltage transformer T1 are connected to a standard signal source device, the first end of the primary side and the second end of the primary side of the precision current transformer T2 are connected to a standard signal source device, the first end of the precision resistor Rc is connected to the first end of the secondary side of the precision current transformer T2, the second end of the precision resistor Rc is connected to the second end of the secondary side of the precision current transformer T2, the first end of the relay K1 of the switching switch is connected to the first end of the secondary side of the precision voltage transformer T1, the second end of the relay K1 of the switching switch is connected to the first end of the precision resistor Rc, and the common end of the relay K1 of the switching switch is connected to the relay K1 of the switching switch The first end of the switching switch or the second end of the relay K1 of the switching switch is connected, the first end of the relay K2 of the switching switch is connected to the second end of the secondary side of the precision voltage transformer T1, the second end of the relay K2 of the switching switch is connected to the second end of the precision resistor Rc, the common end of the relay K2 of the switching switch is connected to the first end of the relay K2 of the switching switch or the second end of the relay K2 of the switching switch, the common end of the relay K2 of the switching switch is connected to the second end of the primary side of the voltage transformer T3 of the delay lead compensation circuit, the non-phase input end of the potential tracking module U11 is connected to the common end of the relay K1 of the switching switch, and the signal output end of the potential tracking module U11 is connected to the inverting input end of the potential tracking module U11 and the first end of the primary side of the voltage transformer T3 of the delay lead compensation circuit.

[0009] Optionally, the front-end driving circuit includes a resistor R4, a resistor R5, a resistor R6, a resistor R7, a second operational amplifier U3 and a first reference voltage U10; the first end of the resistor R4 is connected to the signal output end of the first operational amplifier U1 of the delay lead compensation circuit, the first end of the resistor R5 is connected to the second end of the primary side of the voltage transformer T3 of the delay lead compensation circuit, the first end of the resistor R6 is connected to the second end of the resistor R4, the first end of the resistor R7 is connected to the second end of the resistor R5, the non-inverting input end of the second operational amplifier U3 is connected to the first end of the resistor R6, the inverting input end of the second operational amplifier U3 is connected to the first end of the resistor R7, the first signal output end of the second operational amplifier U3 is connected to the second end of the resistor R6 and the conversion circuit, the second signal output end of the second operational amplifier U3 is connected to the second end of the resistor R7 and the conversion circuit, the first reference voltage U10 is connected to the output common-mode voltage control pin of the second operational amplifier U3, and the first reference voltage U10 is grounded.

[0010] Optionally, the conversion circuit includes an LTC2500-32 conversion chip U2 and a second reference voltage U9; the signal input end of the LTC2500-32 conversion chip U2 is connected to the front-end drive circuit, the signal output end of the LTC2500-32 conversion chip U2 is connected to the main control circuit, the LTC2500-32 conversion chip U2 is grounded, the second reference voltage U9 is connected to the LTC2500-32 conversion chip U2, and the second reference voltage U9 is grounded.

[0011] Optionally, the main control circuit includes a BF609 chip and its peripheral device U4, a display module and an input module; the SPI interface of the BF609 chip and its peripheral device U4 is connected to the conversion circuit, the MII interface of the BF609 chip and its peripheral device U4 is connected to the sending module, the display module is connected to the AMC interface of the BF609 chip and its peripheral device U4, and the input module is connected to the IO port of the BF609 chip and its peripheral device U4.

[0012] Optionally, the sending module includes a physical layer transceiver U5 and a fiber optic transceiver module U6; the input end of the physical layer transceiver U5 is connected to the main control circuit, the input end of the fiber optic transceiver module U6 is connected to the output end of the physical layer transceiver U5, and the output end of the fiber optic transceiver module U6 is used to connect to the tester under test.

[0013] A third aspect of the present invention provides an operating method of a standard electronic transformer, based on the standard electronic transformer provided in any one of the above embodiments, comprising: The mutual inductance circuit collects power data of the standard signal source device, converts the power data according to the standard signal source device, and obtains an initial voltage signal; The delay lead compensation circuit performs voltage division and lead phase shifting according to the initial voltage signal from the mutual inductance circuit to obtain a lead compensation voltage signal; The front-end driving circuit converts the lead compensation voltage signal from the delay lead compensation circuit to obtain a differential voltage signal; The conversion circuit performs digital conversion based on the differential voltage signal from the front-end driving circuit to obtain an initial sampling value; The main control circuit converts the initial sampled value from the conversion circuit to obtain a sampled value message; The sending module transmits the sample value message from the main control circuit to the tester under test.

[0014] Optionally, the main control circuit converts the initial sampled value from the conversion circuit to obtain a sampled value message, including: monitoring whether the actual sampling time reaches the preset sampling time; and determining an initial sampling value from the conversion circuit when the actual sampling time reaches the preset sampling time; Calibration is performed based on a predetermined calibration coefficient and an initial sampling value from a conversion circuit to determine a calibrated initial sampling value; The sampling value message is determined by performing conversion based on the predetermined primary rated value and the calibrated initial sampling value.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The delay lead compensation circuit applied to standard electronic transformers provided by the present invention solves the technical problem that the traditional calibration device in the prior art, when applied to an electronic transformer calibrator or a combined unit calibrator based on the rated delay method, will cause the calibration accuracy to deviate, thereby affecting the safe operation of the power grid and the fairness of metering and billing, causing losses to enterprises or users, and achieves beneficial effects: accurately generating orthogonal components through a voltage divider, combining with a phase shifting circuit to achieve phase advance, and providing a lead compensation amount. When applied to a standard electronic transformer, it can offset the inherent delay of the electronic transformer and subsequent circuits, achieve zero delay output, compensate for the inherent delay, improve the calibration accuracy of the tester based on the rated delay method, and thus reduce losses to enterprises or users.

[0016] The standard electronic mutual inductor provided by the present invention solves the technical problem that the traditional verification device in the prior art, when applied to the electronic mutual inductor calibrator or the combined unit calibrator based on the rated delay method, will cause the deviation of the verification accuracy, thereby affecting the safe operation of the power grid and the fairness of metering and billing, causing losses to enterprises or users, and achieves beneficial effects: the efficient collection and conversion of power data is guaranteed by the mutual inductance circuit, the advance compensation is performed by the delay advance compensation circuit, the inherent delay generated by the subsequent circuit is reduced, and the phase synchronization of the device output signal and the primary side signal is ensured; the compensated voltage signal is converted into a differential voltage signal with stronger anti-interference ability by the front-end driving circuit, thereby improving the stability of signal transmission; the analog is realized by the conversion circuit High-precision conversion of analog signals to digital signals; further processing of digital signals by the main control circuit to obtain sampling value messages, ensuring the accuracy and standardization of data; stable transmission of sampling value messages by the sending module to ensure that the tested tester obtains reliable data; compensation for inherent delay, solving the delay error problem existing in traditional electronic transformers, and also with excellent signal processing capabilities and environmental adaptability, providing a high-precision, high-reliability standard signal source for the calibration of electronic transformer calibrators or combined unit calibrators based on the rated delay method, and is also compatible with the calibration work of electronic transformer calibrators or combined unit calibrators using the synchronous method, thereby improving the calibration accuracy of electronic transformer calibrators or combined unit calibrators, thereby reducing losses to enterprises or users.

[0017] Furthermore, high-fidelity acquisition of power data is achieved by directly connecting the standard signal source equipment through the mutual inductance circuit. Combined with the bidirectional access design of the voltage transformer T3 in the delay lead compensation circuit, a closed-loop feedback path is formed between the primary side and the mutual inductance circuit; through the coordinated connection of the front-end drive circuit and the output end of the delay lead compensation circuit, the lead compensation voltage signal is converted into a differential signal to ensure that the preset accuracy can be maintained in a complex electromagnetic environment; through the cascaded direct connection architecture of the conversion circuit, the main control circuit and the sending module, the full-link delay from analog acquisition to optical fiber transmission is reduced. The overall system has strong compatibility and high reliability, providing a zero-delay, high-precision standard signal source.

[0018] Furthermore, the primary sides of the precision voltage transformer T1 and the precision current transformer T2 are directly connected to the standard signal source device to achieve lossless acquisition of voltage and current signals. Combined with the relay contacts of the switching switch (K1 / K2), the voltage and current signal paths are flexibly switched, making the device compatible with voltage and current detection requirements. The closed-loop connection design between the precision resistor Rc and the secondary side of the current transformer T2 accurately converts the current signal into a voltage signal to reduce errors, and the high input impedance buffer isolation of the potential tracking module U11 eliminates the impact of the secondary side load effect on the transformer accuracy. The delay lead compensation circuit and the mutual inductance circuit are bidirectionally connected through the primary side of the voltage transformer T3 to form a closed-loop feedback compensation mechanism. Combined with the dynamic parameter matching of the phase shift circuit, the preset lead phase compensation is achieved at the preset power frequency, effectively offsetting the inherent delay of the conversion and communication links, providing a highly reliable zero-delay standard signal source for the calibrator under test, thereby avoiding losses caused by unfair calculations for enterprises or users.

[0019] Furthermore, a high common-mode rejection ratio drive circuit is formed by the second operational amplifier U3 and the precision resistor network (R4-R7), which converts the single-ended signal after delay lead compensation into a symmetrical differential signal. Combined with the stable common-mode reference provided by the first reference voltage U10, it ensures that the signal accurately matches the input range of the conversion circuit; the resistor network eliminates impedance mismatch through a four-wire symmetrical layout, reduces the nonlinear error of the differential signal, and provides a standard signal source with strong anti-interference for the calibrator under test, solving the problems of insufficient common-mode suppression and accumulated temperature drift errors in traditional drive circuits.

[0020] Furthermore, high-precision digital sampling is achieved through the 32-bit delay-free composite code output characteristics of the LTC2500-32 conversion chip U2. Combined with the stable reference source design of the second reference voltage U9, the differential signal of the front-end drive circuit is converted into a 24-bit differential voltage code and a 7-bit common-mode voltage code to quantize the error; through the cooperation of the main control chip and optical fiber transmission, zero-delay signal output is achieved, providing a highly reliable, low-latency standardized digital signal source for the calibrator under test, meeting the power system's stringent requirements for real-time performance, anti-interference and long-term stability.

[0021] Furthermore, the high-performance multi-core architecture and SPI interface of the BF609 chip and its peripheral device U4 enable real-time data interaction with the conversion circuit, ensuring zero-delay reading and processing of the initial sampled values. At the same time, the MII interface drives the physical layer transceiver to complete the encapsulation and transmission of the sampled value message, achieving low-latency end-to-end communication. The display module connected through the AMC interface can display the working process in real time. Combined with the flexible configuration function of the input module, it supports rapid on-site operation, solving the problem of system response lag caused by insufficient interface rate or data processing bottleneck in traditional main control solutions.

[0022] The working method of the standard electronic mutual inductor provided by the present invention solves the technical problem that the traditional verification device in the prior art, when applied to the electronic mutual inductor calibrator or the combined unit calibrator based on the rated delay method, will cause the accuracy of the verification work to deviate, thereby affecting the safe operation of the power grid and the fairness of metering and billing, causing losses to enterprises or users, and achieves beneficial effects: the mutual inductance circuit efficiently collects power data and converts it into an initial voltage signal, the delay lead compensation circuit accurately divides the voltage and advances the phase, effectively eliminates the signal transmission delay, and ensures that the output signal is phase-synchronized with the primary side signal; the front-end drive circuit converts the compensated voltage signal into Converted into a differential voltage signal to enhance anti-interference capability; the conversion circuit realizes high-precision digital conversion, and the main control circuit further processes to obtain the sampling value message to ensure data accuracy and standardization; the sending module stably transmits the sampling value message to ensure that the tested instrument obtains reliable data; the modules work together to compensate for the inherent delay and solve the delay error problem of traditional transformers. It also has excellent signal processing capabilities and environmental adaptability, providing a high-precision and highly reliable standard signal source for the calibration of electronic transformer calibrators, merged unit calibrators and other equipment, and effectively promoting the precision and reliability upgrade of the smart substation metering system.

[0023] Furthermore, the calibration coefficient can compensate for the inherent errors in the transformer device hardware and signal transmission process, and eliminate deviations caused by manufacturing processes, environmental factors, etc.; strict monitoring of the actual sampling time and the preset sampling time can ensure the synchronization and timeliness of data acquisition, and avoid measurement inaccuracies caused by sampling time deviations; the initial sampling value is calibrated based on the calibration coefficient to further correct the data error and make the measurement result closer to the true value; according to the preset primary rated value, the calibrated sampling value is uniformly converted into a standard format that complies with the power system measurement specifications, which is convenient for the subsequent accurate calibration of the tested tester. From error compensation, time control to format unification, the high-precision output of the sampling value message is fully guaranteed, providing a reliable calibration basis for the smart substation electronic transformer calibrator or merged unit calibrator, effectively improving the accuracy and stability of power system measurement detection, enhancing the safety and reliability of system operation, and reducing losses to enterprises or users. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings: Figure 1 A circuit diagram of a standard electronic mutual inductor provided in an embodiment of the present invention; Figure 2 A partial flow chart of a working method of a standard electronic mutual inductor provided in another embodiment of the present invention; Among them, 1. Delay advance compensation circuit; 2. Front-end drive circuit; 3. Conversion circuit; 4. Main control circuit; 5. Switch. DETAILED DESCRIPTION

[0025] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0026] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise indicated, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a communication between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] An embodiment of the present invention provides a standard electronic transformer and its delay lead compensation circuit and working method, which are used for the calibration of electronic transformer calibrators or merged unit calibrators. As described in the background technology section, traditional electronic transformer calibrators or merged unit calibrators perform accuracy detection on electronic transformer calibrators and merged unit calibrators based on the synchronization method. When applied to electronic transformer calibrators or merged unit calibrators based on the rated delay method, the accuracy of the calibration work will deviate, thereby affecting the safe operation of the power grid and the fairness of metering and billing, causing losses to enterprises or users.

[0030] like Figure 1 As shown, in a first aspect of the present invention, a delay lead compensation circuit for a standard electronic mutual inductor is provided, comprising: a voltage divider, the voltage divider including a voltage transformer T3, a resistor Ra, and a resistor Rb, wherein a first end of the primary side of the voltage transformer T3 receives an initial voltage signal, a second end of the primary side of the voltage transformer T3 is grounded, a second end of the secondary side of the voltage transformer T3 is connected to the first end of the primary side of the voltage transformer T3, a first end of the resistor Ra is connected to the first end of the secondary side of the voltage transformer T3, a first end of the resistor Rb is connected to the second end of the resistor Ra, and a second end of the resistor Rb is connected to both the second end of the secondary side of the voltage transformer T3 and the first end of the primary side of the voltage transformer T3; The phase-shift circuit includes a resistor R1, a resistor R2, a capacitor C1, a resistor R3, a virtual ground, and a first operational amplifier U1. The first end of the resistor R1 is connected to the second end of the resistor Ra and the first end of the resistor Rb, the first end of the resistor R2 is connected to the second end of the resistor R1, the first end of the capacitor C1 is connected to the second end of the resistor R1, the second end of the resistor Ra, and the first end of the resistor Rb, the first end of the resistor R3 is connected to the second end of the capacitor C1, the virtual ground is connected to the second end of the resistor R3, the second end of the resistor Rb, the second end of the secondary side of the voltage transformer T3, and the first end of the primary side of the voltage transformer T3, the non-inverting input terminal of the first operational amplifier U1 is connected to the second end of the resistor R1 and the first end of the resistor R2, the inverting input terminal of the first operational amplifier U1 is connected to the second end of the capacitor C1 and the first end of the resistor R3, the signal output terminal of the first operational amplifier U1 is connected to the second end of the resistor R2, and the signal output terminal of the first operational amplifier U1 is used to output a lead compensation voltage signal.

[0031] It should be noted that the parameters of resistor R1, resistor R2, capacitor C1 and resistor R3, first operational amplifier U1, voltage transformer T3, resistor Ra, resistor Rb and virtual ground are selected according to actual requirements so that the lead time equivalent to the phase lead can reduce the total delay of the standard electronic transformer used; based on the voltage transformer T3, resistor Ra and resistor Rb, an orthogonal component can be generated; based on the phase shifting circuit, a phase lead compensation voltage signal can be obtained, and the lead compensation voltage signal uses the virtual ground as the reference voltage.

[0032] To achieve a 90-degree lead conversion of the voltage signal, in this embodiment, preferably, the ratio of the primary and secondary coils of the voltage transformer T3 is 1:1, the first operational amplifier U1 is an AD8620, resistors Ra and Rb are metal film resistors with an accuracy of 0.001, the resistance of resistor Ra is 99.99 kΩ, and the resistance of resistor Rb is 10 Ω. The voltage reference of the virtual ground (AGNG) is the initial voltage signal, the amplitude of the phase shift circuit is 1:1, the resistance of resistors R1, R2, and R3 are all 5 kΩ, and the frequency is 50 Hz. It should be noted that the implementation process is as follows: Assume that the input of the phase shift circuit is , the output is , then the first formula is: , ; Since both resistors R1 and R2 are 5kΩ, we have the second formula: ; Since the resistance of resistor R3 is 5kΩ and the frequency is 50Hz, , Then there is the third formula: ; Where R1 is the resistance of resistor R1, R2 is the resistance of resistor R2, R3 is the resistance of resistor R3, and j is an imaginary unit that satisfies ,π is the ratio of circumference to diameter, f is the frequency, C1 is the capacitance value of capacitor C1; The phase-shifting circuit performs a 2us lead compensation on the quadrature component of the analog quantity ΔU, which is converted to an angle difference of 2.16 minutes, that is, it provides a phase compensation of 2.16 minutes for the quadrature component ΔU. This phase-compensated quadrature component is superimposed on the initial voltage signal U to obtain U+ΔU. Thus, the lead compensation circuit realizes a 90-degree lead conversion of the output signal according to the input signal. When the total delay of the standard electronic transformer used is also 2us, zero-delay output is achieved.

[0033] Therefore, the delay lead compensation circuit applied to the standard electronic transformer provided by the present invention solves the technical problem that the traditional calibration device in the prior art, when applied to the electronic transformer calibrator or the combined unit calibrator based on the rated delay method, will cause the calibration accuracy to deviate, thereby affecting the safe operation of the power grid and the fairness of metering and billing, causing losses to enterprises or users, and achieves beneficial effects: the orthogonal components are accurately generated by the voltage divider, and the phase advance is achieved in combination with the phase shifting circuit to provide a lead compensation amount. When applied to the standard electronic transformer, the inherent delay of the electronic transformer and the subsequent circuit can be offset to achieve zero delay output, compensate for the inherent delay, and improve the calibration accuracy of the tester based on the rated delay method, thereby reducing the losses of enterprises or users.

[0034] In a second aspect of the present invention, a standard electronic mutual inductor is provided, comprising the delay lead compensation circuit 1 for a standard electronic mutual inductor provided in the above embodiment, and further comprising a mutual inductance circuit, a front-end drive circuit 2, a conversion circuit 3, a main control circuit 4 and a sending module; wherein, A mutual inductance circuit is used to collect power data of a standard signal source device, convert the power data of the standard signal source device, and obtain an initial voltage signal; The delay lead compensation circuit 1 is used to divide the voltage and advance the phase according to the initial voltage signal from the mutual inductance circuit to obtain an advance compensation voltage signal; The front-end driving circuit 2 is used to convert the lead compensation voltage signal from the delay lead compensation circuit 1 to obtain a differential voltage signal; The conversion circuit 3 is used to perform digital conversion based on the differential voltage signal from the front-end driving circuit 2 to obtain an initial sampling value; The main control circuit 4 is used to convert the initial sampled value from the conversion circuit 3 to obtain a sampled value message; The sending module is used to transmit the sample value message from the main control circuit 4 to the tester under test.

[0035] It should be noted that the standard signal source device refers to a device or apparatus that can generate a specific type of stable and repeatable signal, and the standard signal source device can be used in the laboratory; the power data of the standard signal source device is the voltage data and / or current data generated by the standard signal source device. In this embodiment, preferably, the power data of the standard signal source device is a standard voltage signal and / or a standard current signal; the tester under test is an electronic transformer tester or a combined unit tester; in this embodiment, preferably, the conversion circuit 3 is an AD conversion circuit, the initial sampling value is an AD sampling value, and the front-end drive circuit 2 is an AD front-end drive circuit; in order to achieve automation, in this embodiment, the main control circuit 4 is also used to generate a control signal, and the mutual inductance circuit is also used to receive a control signal from the main control circuit 4; in this embodiment, preferably, the sampling value message is an IEC61850-9-2 sampling value message.

[0036] Thus, the mutual inductance circuit ensures efficient collection and conversion of power data. The delay advance compensation circuit 1 performs advance compensation to minimize the inherent delay generated by subsequent circuits, ensuring that the output signal of the device is phase-synchronized with the primary-side signal. The front-end drive circuit 2 converts the compensated voltage signal into a differential voltage signal with stronger anti-interference capability, improving signal transmission stability. The conversion circuit 3 achieves high-precision conversion from analog signals to digital signals. The main control circuit 4 further processes the digital signal to obtain a sampled value message, ensuring data accuracy and standardization. The sending module stably transmits the sampled value message, ensuring that the tester under test obtains reliable data. The inherent delay is compensated, solving the delay error problem existing in traditional electronic transformers. The device also has excellent signal processing capabilities and environmental adaptability, providing a high-precision and highly reliable standard signal source for the calibration of electronic transformer calibrators or combined unit calibrators based on the rated delay method. The device is also compatible with the calibration of electronic transformer calibrators or combined unit calibrators using the synchronization method, improving the calibration accuracy of electronic transformer calibrators or combined unit calibrators, thereby reducing losses to enterprises or users.

[0037] In one embodiment, the mutual inductance circuit is connected to a standard signal source device, the first primary side end and the second primary side end of the voltage transformer T3 of the delay lead compensation circuit 1 are both connected to the mutual inductance circuit, the front-end drive circuit 2 is connected to the second primary side end of the voltage transformer T3 of the delay lead compensation circuit 1 and the signal output end of the first operational amplifier U1, the conversion circuit 3 is connected to the front-end drive circuit 2, the main control circuit 4 is connected to the conversion circuit 3, the sending module is connected to the main control circuit 4, and the sending module is connected to the tester under test. Therefore, high-fidelity acquisition of power data is achieved by directly connecting the standard signal source equipment through the mutual inductance circuit. Combined with the bidirectional access design of the voltage transformer T3 in the delay lead compensation circuit 1, a closed-loop feedback path is formed between the primary side and the mutual inductance circuit; through the coordinated connection of the front-end drive circuit 2 and the output end of the delay lead compensation circuit 1, the lead compensation voltage signal is converted into a differential signal to ensure that the preset accuracy can be maintained in a complex electromagnetic environment; through the cascaded direct connection architecture of the conversion circuit 3, the main control circuit 4 and the sending module, the full-link delay from analog quantity acquisition to optical fiber transmission is reduced, the overall system has strong compatibility and high reliability, and provides a zero-delay, high-precision standard signal source.

[0038] In one embodiment, the mutual induction circuit includes a precision voltage transformer T1, a precision current transformer T2, a precision resistor Rc, a switching switch 5 and a potential tracking module U11; the first end of the primary side and the second end of the primary side of the precision voltage transformer T1 are connected to a standard signal source device, the first end of the primary side and the second end of the primary side of the precision current transformer T2 are connected to the standard signal source device, the first end of the precision resistor Rc is connected to the first end of the secondary side of the precision current transformer T2, the second end of the precision resistor Rc is connected to the second end of the secondary side of the precision current transformer T2, the first end of the relay K1 of the switching switch 5 is connected to the first end of the secondary side of the precision voltage transformer T1, the second end of the relay K1 of the switching switch 5 is connected to the first end of the precision resistor Rc and the first end of the secondary side of the precision current transformer T2, and the common end of the relay K1 of the switching switch 5 is connected to the first end of the relay K1 of the switching switch 5 or the relay of the switching switch 5. The second end of K1 is connected, the first end of the relay K2 of the switching switch 5 is connected to the second end of the secondary side of the precision voltage transformer T1, the second end of the relay K2 of the switching switch 5 is connected to the second end of the precision resistor Rc and the second end of the secondary side of the precision current transformer T2, the common end of the relay K2 of the switching switch 5 is connected to the first end of the relay K2 of the switching switch 5 or the second end of the relay K2 of the switching switch 5, the common end of the relay K2 of the switching switch 5 is connected to the second end of the primary side of the voltage transformer T3 of the delay lead compensation circuit 1 and the front-end drive circuit 2, the common end of the relay K2 of the switching switch 5 is grounded, the non-phase input end of the potential tracking module U11 is connected to the common end of the relay K1 of the switching switch 5, and the signal output end of the potential tracking module U11 is connected to the inverting input end of the potential tracking module U11 and the first end of the primary side of the voltage transformer T3 of the delay lead compensation circuit 1.

[0039] It should be noted that in this embodiment, preferably, the primary side voltage of the precision voltage transformer T1 is 100V, the primary side current of the precision current transformer T2 is 5A, and the secondary side voltage signals of the precision voltage transformer T1 and the precision current transformer T2 are 1V standard voltage; the potential tracking module U11 adopts the operational amplifier AD8620; the precision voltage transformer T1, the precision current transformer T2, and the precision resistor Rc can be selected according to actual needs. In this embodiment, preferably, the precision voltage transformer T1 is a bipolar precision voltage transformer T1 with a ratio of 100:1, an accuracy of 0.001 level, a ratio difference ≤0.001%, and an angle difference ≤0.03 minutes; the precision current transformer T2 is a zero flux current transformer with a ratio of 500:1, an accuracy of 0.001 level, a ratio difference ≤0.001%, and an angle difference ≤0.03 minutes; the precision resistor Rc is a 100 ohm precision resistor with a maximum allowable error of ±0.001%.

[0040] Therefore, by directly connecting the primary sides of the precision voltage transformer T1 and the precision current transformer T2 to the standard signal source device, non-destructive acquisition of voltage and current signals is achieved. Combined with the relay contacts of the switching switch 5 (K1 / K2), the voltage and current signal paths can be flexibly switched, making the device compatible with voltage and current detection requirements. The closed-loop connection design between the precision resistor Rc and the secondary side of the current transformer T2 accurately converts the current signal into a voltage signal, reducing errors. The high input impedance buffer isolation of the potential tracking module U11 eliminates the impact of the secondary side load effect on the transformer accuracy. The delay lead compensation circuit 1 and the mutual inductance circuit are bidirectionally connected through the primary side of the voltage transformer T3 to form a closed-loop feedback compensation mechanism. Combined with the dynamic parameter matching of the phase shift circuit, the preset lead phase compensation is achieved at the preset power frequency, effectively offsetting the inherent delay of the conversion and communication links, providing a highly reliable zero-delay standard signal source for the tester under test, thereby avoiding losses caused by unfair calculations for enterprises or users. In one embodiment, the front-end driving circuit 2 includes a resistor R4, a resistor R5, a resistor R6, a resistor R7, a second operational amplifier U3 and a first reference voltage U10; the first end of the resistor R4 is connected to the signal output end of the first operational amplifier U1 of the delay lead compensation circuit 1, the first end of the resistor R5 is connected to the second end of the primary side of the voltage transformer T3 of the delay lead compensation circuit 1, the first end of the resistor R6 is connected to the second end of the resistor R4, the first end of the resistor R7 is connected to the second end of the resistor R5, the non-inverting input end of the second operational amplifier U3 is connected to the first end of the resistor R6, the inverting input end of the second operational amplifier U3 is connected to the first end of the resistor R7, the first signal output end of the second operational amplifier U3 is connected to the second end of the resistor R6 and the conversion circuit 3, the second signal output end of the second operational amplifier U3 is connected to the second end of the resistor R7 and the conversion circuit 3, the first reference voltage U10 is connected to the output common-mode voltage control pin of the second operational amplifier U3, and the first reference voltage U10 is grounded.

[0041] It should be noted that the resistors R4, R5, R6 and R7 can be selected according to actual needs. In this embodiment, preferably, the resistors R4, R5, R6 and R7 are metal film resistors with a temperature drift of 1ppm, the resistance value is 1kΩ, and the maximum allowable error is ±0.001%; ​​the second operational amplifier U3 is preferably the operational amplifier OPA1632, and the operational amplifier OPA1632 has an ultra-low distortion of 0.000022%; the first reference voltage U10 is preferably the reference voltage ADR441B, and the voltage value output by the reference voltage ADR441B is 2.5V, which can increase the driving current and provide a common-mode voltage of 2.5V at the same time.

[0042] Therefore, a high common-mode rejection ratio drive circuit is formed by the fully differential operational amplifier OPA1632 and the precision resistor network (R4-R7), which converts the single-ended signal after delay lead compensation into a symmetrical differential signal. Combined with the stable common-mode reference provided by the first reference voltage U10, it ensures that the signal accurately matches the input range of the conversion circuit 3; the resistor network eliminates impedance mismatch through a four-wire symmetrical layout and reduces the nonlinear error of the differential signal. At the same time, the ultra-low distortion characteristics of the operational amplifier OPA1632 effectively suppress high-frequency noise in the transmission link, providing the calibrator under test with a standard signal source with strong anti-interference and small temperature drift, solving the problems of insufficient common-mode suppression and accumulated temperature drift errors in traditional drive circuits.

[0043] In one embodiment, the conversion circuit 3 includes an LTC2500-32 conversion chip U2 and a second reference voltage U9; the signal input end of the LTC2500-32 conversion chip U2 is connected to the front-end drive circuit 2, the signal output end of the LTC2500-32 conversion chip U2 is connected to the main control circuit 4, the LTC2500-32 conversion chip U2 is grounded, the second reference voltage U9 is connected to the LTC2500-32 conversion chip U2, and the second reference voltage U9 is grounded.

[0044] It should be noted that the common-mode voltage input range of the LTC2500-32 conversion chip U2 is 0~5V, and the LTC2500-32 conversion chip U2 has an integral nonlinearity of ±0.5ppm. Although the LTC2500-32 conversion chip uses a delay-free channel for fast conversion, the sampling of the conversion circuit 3 requires 0.327us, the conversion requires 1us, and the data output requires 0.32us. When the subsequent cable uses Ethernet packaging and transmission, the Ethernet packaging and transmission requires 0.35us, and the total delay is 1.997us, which is approximately equal to 2us; the second reference voltage U9 is preferably the reference voltage ADR445B. The reference voltage ADR445B is a voltage reference chip with a temperature drift of 3ppm / °C and an initial accuracy of 0.04%.

[0045] Therefore, high-precision digital sampling is achieved through the 32-bit delay-free composite code output characteristics of the LTC2500-32 conversion chip U2. Combined with the stable reference source design of the second reference voltage U9, the differential signal of the front-end drive circuit 2 is converted into a 24-bit differential voltage code and a 7-bit common-mode voltage code to quantize the error; through the cooperation of the main control chip and optical fiber transmission, zero-delay signal output is achieved, providing a highly reliable, low-latency standardized digital signal source for the calibrator under test, meeting the power system's stringent requirements for real-time, anti-interference and long-term stability.

[0046] In one embodiment, the main control circuit 4 includes a BF609 chip and its peripheral device U4, a display module and an input module; the SPI interface of the BF609 chip and its peripheral device U4 is connected to the conversion circuit 3, the MII interface of the BF609 chip and its peripheral device U4 is connected to the sending module, the display module is connected to the AMC interface of the BF609 chip and its peripheral device U4, and the input module is connected to the IO port of the BF609 chip and its peripheral device U4.

[0047] It should be noted that the BF609 chip and its peripheral device U4 have a large number of built-in interfaces, including 2 Ethernet MII interfaces, 16 general IO ports, an AMC interface (asynchronous memory interface), etc., and are equipped with 256Mbyte DRAM; the display module is a liquid crystal display module (LCD U8), which is used to receive display signals from the BF609 chip and its peripheral device U4; the input module is a keyboard (KEY U7), which is used to input control commands, where the control command can be to select the precision voltage transformer T1 or the precision current transformer T2, or to select exit to end the operation; when the conversion circuit 3 includes a second reference voltage U9, in order to calibrate the initial accuracy of the second reference voltage U9 to within 0.001%, in this embodiment, preferably, the BF609 chip is used to obtain the initial voltage value of the second reference voltage U9, calculate according to the initial voltage value of the second reference voltage U9, obtain a calibration coefficient, and calibrate based on the calibration coefficient and the initial sampling value from the LTC2500-32 conversion chip U2 to obtain a calibrated initial sampling value.

[0048] Therefore, real-time data interaction with the conversion circuit 3 is achieved through the high-performance multi-core architecture and SPI interface of the BF609 chip and its peripheral device U4, ensuring zero-delay reading and processing of the initial sample value. At the same time, the physical layer transceiver is driven by the MII interface to complete the encapsulation and transmission of the sample value message, realizing low-latency end-to-end communication; the display module connected through the AMC interface can display the working process in real time, combined with the flexible configuration function of the input module, to support fast on-site operation, and solve the problem of system response lag caused by insufficient interface rate or data processing bottleneck in traditional main control solutions.

[0049] In one embodiment, the sending module includes a physical layer transceiver U5 and a fiber optic transceiver module U6; the input end of the physical layer transceiver U5 is connected to the main control circuit 4, the input end of the fiber optic transceiver module U6 is connected to the output end of the physical layer transceiver U5, and the output end of the fiber optic transceiver module U6 is used to connect to the tester under test. It should be noted that the physical layer transceiver can be a module composed of a main chip RTL8201BL to realize all 10 / 100M Ethernet physical layer functions; the fiber optic transceiver module adopts a communication fiber optic component and is usually used as a fiber optic transmitter, receiver or transceiver, with a transmission rate of up to 100Mb / s. Therefore, the sampling value message generated by the main control circuit 4 is encapsulated in an Ethernet frame and modulated into an electrical signal by the physical layer transceiver U5, and the fiber optic transceiver module U6 is driven to complete the photoelectric conversion, and the optical signal is transmitted to the tester under test through the optical fiber, ensuring the integrity and real-time performance of the sampling value data, and providing a seamless communication link for high-precision, high-reliability zero-delay detection.

[0050] In one embodiment, the device further includes a power module P1, which is connected to the mutual inductance circuit, the delay lead compensation circuit 1, the front-end driver circuit 2, the conversion circuit 3, and the main control circuit 4. It should be noted that the power module P1 is used to provide power to the mutual inductance circuit, the delay lead compensation circuit 1, the front-end driver circuit 2, the conversion circuit 3, and the main control circuit 4. In this embodiment, the output of the power module P1 includes one VDD, 5V, 2A channel, one VSS, -5V, 2A channel, one +3.3V, 2A channel, and one +1.8V, 2A channel. This provides independent power supply for the device.

[0051] It should also be noted that the present invention can be used to test an electronic transformer tester under test based on the JJF 1995-2022 Calibration Specification for Electronic Transformer Testers; the present invention can be used to test a merging unit tester under test based on the JJF 2027-2023 Calibration Specification for Transformer Merging Unit Testers; the device of the present invention must meet the following conditions: The accuracy of the precision voltage transformer T1 or the precision current transformer T2 is (Ep): 0.001 level; The conversion resistance accuracy is (Er): 0.001 level; The relative accuracy of delay lead compensation is (Ed): 2us / 20ms×1.0%=1ppm; The accuracy of the AD front-end driver circuit is (Ea): , The accuracy of the four resistors is 0.001 level; The accuracy of AD conversion is (Ead): 0.5ppm; Accuracy of reference voltage after calibration (Eref) (23°C): 0.001 level; The output voltage primary rating is 220kV, and the digital quantization error (Edv) is: 10mV / 220kV=0.045ppm; The output current primary rating is 1000A, and the digital quantization error (Edi) is: 1mA / 1000A=1ppm; Then, when the power data collected from the standard signal source device is voltage, the amplitude accuracy Ev(f) of the device can be approximately calculated as: ; The phase accuracy Ev(φ) of the device can be approximately calculated as: ; When the power data collected from the standard signal source device is current, the amplitude accuracy Ev(f) of the device based on the precision current transformer T2 can be approximately calculated as: ; The phase accuracy Ev (φ) of the device based on the precision current transformer T2 can be approximately calculated as: ; Thus, a standard electronic transformer with zero delay is realized.

[0052] A third aspect of the present invention provides an operating method of a standard electronic transformer, based on the standard electronic transformer provided in any one of the above embodiments, comprising: S1: The mutual inductance circuit collects the power data of the standard signal source device and converts it according to the power data of the standard signal source device to obtain the initial voltage signal; S2: The delay lead compensation circuit 1 performs voltage division and lead phase shifting according to the initial voltage signal from the mutual inductance circuit to obtain a lead compensation voltage signal; S3: The front-end driving circuit 2 converts the lead compensation voltage signal from the delay lead compensation circuit 1 to obtain a differential voltage signal; S4: The conversion circuit 3 performs digital conversion based on the differential voltage signal from the front-end driving circuit 2 to obtain an initial sampling value; S5: The main control circuit 4 converts the initial sampled value from the conversion circuit 3 to obtain a sampled value message; S6: The sending module transmits the sample value message from the main control circuit 4 to the tester under test.

[0053] As a result, the mutual inductance circuit efficiently collects power data and converts it into an initial voltage signal. The delay advance compensation circuit 1 accurately divides the voltage and advances the phase, effectively eliminating the signal transmission delay and ensuring that the output signal is phase-synchronized with the primary-side signal. The front-end drive circuit 2 converts the compensated voltage signal into a differential voltage signal to enhance the anti-interference capability. The conversion circuit 3 realizes high-precision digital conversion, and the main control circuit 4 further processes it to obtain the sampled value message to ensure data accuracy and standardization. The sending module stably transmits the sampled value message to ensure that the tested instrument obtains reliable data. The modules work together to solve the delay error problem of traditional mutual inductors, and also have excellent signal processing capabilities and environmental adaptability, providing a high-precision and highly reliable standard signal source for the calibration of electronic mutual inductor calibrators, merged unit calibrators and other equipment, effectively promoting the precision and reliability upgrade of the smart substation metering system.

[0054] In one embodiment, before step S1, the method further includes: The main control circuit 4 collects control commands and generates control signals and power data type flags of standard signal source devices; The mutual induction circuit receives and executes the control signal from the main control circuit 4 .

[0055] In one embodiment, the main control circuit 4 collects control commands and generates control signals and power data type flags of standard signal source devices, including: Collect control commands; Based on the control command, a control signal is generated; Based on the control signal, the power data type flag of the standard signal source device is determined; wherein, If the control signal is to select the precision voltage transformer T1, the power data type flag of the standard signal source device is flag=0; If the control signal is to select the precision current transformer T2, the power data type flag of the standard signal source device is flag=1.

[0056] It should be noted that the input module can be used to collect control commands.

[0057] In one embodiment, the mutual induction circuit receives and executes the control signal from the main control circuit 4, including: Receive a control signal from the main control circuit 4; Based on the control signal, determine the closed position of relay K1 and relay K2 of switch 5; The relay K1 and the relay K2 of the changeover switch 5 are closed based on the closed position of the relay K1 and the relay K2 of the changeover switch 5 .

[0058] In one embodiment, the main control circuit 4 performs conversion according to the initial sampled value from the conversion circuit 3 to obtain a sampled value message, including: monitoring whether the actual sampling time reaches the preset sampling time; if the actual sampling time reaches the preset sampling time, determining the initial sampling value from the conversion circuit 3; Calibrate according to a predetermined calibration coefficient and the initial sampling value from the conversion circuit 3 to determine the calibrated initial sampling value; The sampling value message is determined by performing conversion based on the predetermined primary rated value and the calibrated initial sampling value.

[0059] It should be noted that the primary rated value is preset to 220kV or 1000A; the calibration coefficient is between 0.9996 and 1.0004, and the factory default calibration coefficient is 1.

[0060] Therefore, the calibration coefficient can compensate for the inherent errors in the transformer device hardware and signal transmission process, and eliminate deviations caused by manufacturing processes, environmental factors, etc.; strict monitoring of the actual sampling time and the preset sampling time can ensure the synchronization and timeliness of data acquisition, and avoid measurement inaccuracies caused by sampling time deviations; the initial sampling value is calibrated based on the calibration coefficient to further correct the data error and make the measurement result closer to the true value; according to the preset primary rated value, the calibrated sampling value is uniformly converted into a standard format that complies with the power system measurement specifications, which is convenient for the subsequent accurate calibration of the tested tester. From error compensation, time control to format unification, the high-precision output of the sampling value message is fully guaranteed, providing a reliable calibration basis for the smart substation electronic transformer calibrator or merged unit calibrator, effectively improving the accuracy and stability of power system measurement detection, enhancing the safety and reliability of system operation, and reducing losses to enterprises or users.

[0061] In one embodiment, the calibration coefficient is determined by the following method, comprising: monitoring whether the second reference voltage U9 needs to be calibrated; if the second reference voltage U9 needs to be calibrated, obtaining an initial voltage value of the second reference voltage U9; The calibration coefficient is obtained by performing calculation based on the initial voltage value of the second reference voltage U9.

[0062] It should be noted that, in this embodiment, preferably, the second reference voltage U9 is the reference voltage ADR445B, and the initial voltage value of the reference voltage ADR445B can be accurately measured using a reference standard voltmeter.

[0063] In one embodiment, the calibration coefficient is obtained by calculation based on the initial voltage value of the second reference voltage U9 using the following formula: , in, is the calibration coefficient, is the initial voltage value of the second reference voltage U9.

[0064] In one embodiment, the primary rating is determined by the following method, including: Determine the primary rated value based on the power data type mark of the standard signal source device and the preset primary rated value.

[0065] Therefore, the working method of the standard electronic mutual inductor provided by the present invention solves the technical problem that the traditional calibration device in the prior art, when applied to the electronic mutual inductor calibrator or the combined unit calibrator based on the rated delay method, will cause the calibration work accuracy to deviate, thereby affecting the safe operation of the power grid and the fairness of metering and billing, causing losses to enterprises or users, and achieves beneficial effects: the mutual inductance circuit efficiently collects power data and converts it into an initial voltage signal, the delay advance compensation circuit 1 accurately divides the voltage and advances the phase, effectively eliminating the signal transmission delay, and ensuring that the output signal is synchronized with the primary side signal phase; the front-end drive circuit 2 will compensate The voltage signal after measurement is converted into a differential voltage signal to enhance anti-interference capability; the conversion circuit 3 realizes high-precision digital conversion, and the main control circuit 4 further processes to obtain the sampling value message to ensure data accuracy and standardization; the sending module stably transmits the sampling value message to ensure that the tested instrument obtains reliable data; the modules work together to solve the delay error problem existing in traditional transformers, and also have excellent signal processing capabilities and environmental adaptability, providing a high-precision and highly reliable standard signal source for the calibration of electronic transformer calibrators, merged unit calibrators and other equipment, which effectively promotes the precision and reliability upgrade of the smart substation metering system.

[0066] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0067] It is understood from common technical knowledge that the present invention may be implemented by other embodiments that do not depart from its spirit or essential features. Therefore, the embodiments disclosed above are, in all respects, merely illustrative and not exclusive. All modifications within the scope of the present invention or equivalent to the scope of the present invention are intended to be encompassed by the present invention.

Claims

1. A delay lead compensation circuit for a standard electronic mutual inductor, characterized in that: include: a voltage divider, the voltage divider including a voltage transformer T3, a resistor Ra, and a resistor Rb, wherein a first end of the primary side of the voltage transformer T3 receives an initial voltage signal, a second end of the primary side of the voltage transformer T3 is grounded, a second end of the secondary side of the voltage transformer T3 is connected to the first end of the primary side of the voltage transformer T3, a first end of the resistor Ra is connected to the first end of the secondary side of the voltage transformer T3, a first end of the resistor Rb is connected to the second end of the resistor Ra, and a second end of the resistor Rb is connected to the second end of the secondary side of the voltage transformer T3; The phase-shift circuit includes a resistor R1, a resistor R2, a capacitor C1, a resistor R3, a virtual ground, and a first operational amplifier U1. The first end of the resistor R1 is connected to the first end of the resistor Rb, the first end of the resistor R2 is connected to the second end of the resistor R1, the first end of the capacitor C1 is connected to the first end of the resistor R1, the first end of the resistor R3 is connected to the second end of the capacitor C1, the virtual ground is connected to the second end of the resistor R3 and the second end of the resistor Rb, the non-inverting input end of the first operational amplifier U1 is connected to the first end of the resistor R2, the inverting input end of the first operational amplifier U1 is connected to the first end of the resistor R3, the signal output end of the first operational amplifier U1 is connected to the second end of the resistor R2, and the signal output end of the first operational amplifier U1 is used to output a lead compensation voltage signal.

2. A standard electronic mutual inductor, characterized in that: The delay lead compensation circuit for a standard electronic mutual inductor according to claim 1 further comprises a mutual inductance circuit, a front-end drive circuit, a conversion circuit, a main control circuit and a sending module; wherein, The mutual inductance circuit is used to collect power data of the standard signal source device and convert the power data of the standard signal source device to obtain an initial voltage signal; The time delay lead compensation circuit is used to divide the voltage and advance the phase according to the initial voltage signal from the mutual inductance circuit to obtain an advance compensation voltage signal; A front-end driving circuit is used to convert the lead compensation voltage signal from the delay lead compensation circuit to obtain a differential voltage signal; A conversion circuit, configured to perform digital conversion based on the differential voltage signal from the front-end driving circuit to obtain an initial sampling value; A main control circuit is used to convert the initial sampled values ​​from the conversion circuit to obtain a sampled value message; The sending module is used to transmit the sampling value message of the future autonomous control circuit to the tester under test.

3. The standard electronic mutual inductor according to claim 2, characterized in that: The mutual inductance circuit is connected to the standard signal source equipment, the first end of the primary side and the second end of the primary side of the voltage transformer T3 of the delay lead compensation circuit are both connected to the mutual inductance circuit, the front-end drive circuit is connected to the second end of the primary side of the voltage transformer T3 of the delay lead compensation circuit and the signal output end of the first operational amplifier U1, the conversion circuit is connected to the front-end drive circuit, the main control circuit is connected to the conversion circuit, the sending module is connected to the main control circuit, and the sending module is connected to the tester under test.

4. The standard electronic mutual inductor according to claim 2, characterized in that: The mutual induction circuit includes a precision voltage transformer T1, a precision current transformer T2, a precision resistor Rc, a switching switch and a potential tracking module U11; the first end of the primary side and the second end of the primary side of the precision voltage transformer T1 are connected to a standard signal source device, the first end of the primary side and the second end of the primary side of the precision current transformer T2 are connected to a standard signal source device, the first end of the precision resistor Rc is connected to the first end of the secondary side of the precision current transformer T2, the second end of the precision resistor Rc is connected to the second end of the secondary side of the precision current transformer T2, the first end of the relay K1 of the switching switch is connected to the first end of the secondary side of the precision voltage transformer T1, the second end of the relay K1 of the switching switch is connected to the first end of the precision resistor Rc, and the common end of the relay K1 of the switching switch is connected to the first end of the relay K1 of the switching switch. One end or the second end of the relay K1 of the switching switch is connected, the first end of the relay K2 of the switching switch is connected to the second end of the secondary side of the precision voltage transformer T1, the second end of the relay K2 of the switching switch is connected to the second end of the precision resistor Rc, the common end of the relay K2 of the switching switch is connected to the first end of the relay K2 of the switching switch or the second end of the relay K2 of the switching switch, the common end of the relay K2 of the switching switch is connected to the second end of the primary side of the voltage transformer T3 of the delay lead compensation circuit, the non-phase input end of the potential tracking module U11 is connected to the common end of the relay K1 of the switching switch, and the signal output end of the potential tracking module U11 is connected to the inverting input end of the potential tracking module U11 and the first end of the primary side of the voltage transformer T3 of the delay lead compensation circuit.

5. The standard electronic mutual inductor according to claim 2, characterized in that: The front-end driving circuit includes a resistor R4, a resistor R5, a resistor R6, a resistor R7, a second operational amplifier U3 and a first reference voltage U10; the first end of the resistor R4 is connected to the signal output end of the first operational amplifier U1 of the delay lead compensation circuit, the first end of the resistor R5 is connected to the second end of the primary side of the voltage transformer T3 of the delay lead compensation circuit, the first end of the resistor R6 is connected to the second end of the resistor R4, the first end of the resistor R7 is connected to the second end of the resistor R5, the non-inverting input end of the second operational amplifier U3 is connected to the first end of the resistor R6, the inverting input end of the second operational amplifier U3 is connected to the first end of the resistor R7, the first signal output end of the second operational amplifier U3 is connected to the second end of the resistor R6 and the conversion circuit, the second signal output end of the second operational amplifier U3 is connected to the second end of the resistor R7 and the conversion circuit, the first reference voltage U10 is connected to the output common-mode voltage control pin of the second operational amplifier U3, and the first reference voltage U10 is grounded.

6. The standard electronic mutual inductor according to claim 2, characterized in that: The conversion circuit includes an LTC2500-32 conversion chip U2 and a second reference voltage U9; the signal input end of the LTC2500-32 conversion chip U2 is connected to the front-end drive circuit, the signal output end of the LTC2500-32 conversion chip U2 is connected to the main control circuit, the LTC2500-32 conversion chip U2 is grounded, the second reference voltage U9 is connected to the LTC2500-32 conversion chip U2, and the second reference voltage U9 is grounded.

7. The standard electronic mutual inductor according to claim 2, characterized in that: The main control circuit includes a BF609 chip and its peripheral device U4, a display module and an input module; the SPI interface of the BF609 chip and its peripheral device U4 is connected to the conversion circuit, the MII interface of the BF609 chip and its peripheral device U4 is connected to the sending module, the display module is connected to the AMC interface of the BF609 chip and its peripheral device U4, and the input module is connected to the IO port of the BF609 chip and its peripheral device U4.

8. The standard electronic mutual inductor according to claim 2, characterized in that: The sending module includes a physical layer transceiver U5 and a fiber optic transceiver module U6; the input end of the physical layer transceiver U5 is connected to the main control circuit, the input end of the fiber optic transceiver module U6 is connected to the output end of the physical layer transceiver U5, and the output end of the fiber optic transceiver module U6 is used to connect to the tester under test.

9. A method for operating a standard electronic mutual inductor, characterized in that: The standard electronic transformer according to any one of claims 2 to 8, comprising: The mutual inductance circuit collects power data of the standard signal source device, converts the power data according to the standard signal source device, and obtains an initial voltage signal; The delay lead compensation circuit performs voltage division and lead phase shifting according to the initial voltage signal from the mutual inductance circuit to obtain a lead compensation voltage signal; The front-end driving circuit converts the lead compensation voltage signal from the delay lead compensation circuit to obtain a differential voltage signal; The conversion circuit performs digital conversion based on the differential voltage signal from the front-end driving circuit to obtain an initial sampling value; The main control circuit converts the initial sampled value from the conversion circuit to obtain a sampled value message; The sending module transmits the sample value message from the main control circuit to the tester under test.

10. The operating method of the standard electronic mutual inductor according to claim 9, characterized in that: The main control circuit converts the initial sampled value from the conversion circuit to obtain a sampled value message, including: monitoring whether the actual sampling time reaches the preset sampling time; and determining an initial sampling value from the conversion circuit when the actual sampling time reaches the preset sampling time; Calibration is performed based on a predetermined calibration coefficient and an initial sampling value from a conversion circuit to determine a calibrated initial sampling value; The sampling value message is determined by performing conversion based on the predetermined primary rated value and the calibrated initial sampling value.

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